Ideally, an internal combustion engine is completely sealed, and vacuum leaks in such a system can result in problems ranging from decreased operating efficiency to engine failure. Detecting leaks can be a painstaking, time consuming, and often inefficient process. Accordingly, a variety of leak-detection systems, apparatus, and methods have been adapted. For example, U.S. Pat. No. 6,907,771 discloses, in part, a leak detecting apparatus that connects to a conventional air supply which provides air under pressure, the air being routed through a fluid tank where the air is directed against fluid to generate fog. U.S. Pat. No. 5,107,698 discloses, in part, an in situ vacuum leak detector where smoke is generated from a suitable smoke generating fluid in a chamber means, and sealably communicated to the intake manifold of a vacuum system of an internal combustion engine.
In considering a specific application, an actuated fault lamp for an example Ford 6.01t f250 engine, a typical diagnostic workup for an illuminated check-engine lamp may require verification that the intake and system are free of air leaks. This is particularly true where the lamp illumination is attributable to the On Board Diagnostic System II (OBD-II) generating fault code p0401 signaling inadequate Exhaust Gas Recirculation (EGR) flow detected by the Differential Pressure Feedback (DPFE) sensor. A common methodology to further determine the nature of this problem is to pump smoke into the Manifold Absolute Pressure (MAP) port followed by pressurization with shop air through the MAP port while blocking both the Intake Air Temp 2 (IAT2) port and the exhaust tail pipe. This method is problematic in that it is time consuming and inadequately detects leaks. A further weakness of this method is that the system is not pressurized in the same direction as normal operating conditions and therefore does not most accurately stress system seals. What is needed is an apparatus permitting quick and reliable leak detection. What is further needed is a leak detector apparatus permitting more accurate stressing of seals, emulating the engine's natural operating environment, by pressurizing the engine in the same direction as drive conditions.